Ruenwongsa P, Luanvararat M, O'Sullivan W J
Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand.
Mol Biochem Parasitol. 1989 Mar 15;33(3):265-71. doi: 10.1016/0166-6851(89)90088-1.
Serine hydroxymethyltransferase (EC 2.1.2.1) was partially purified from a pyrimethamine sensitive strain of Plasmodium chabaudi. Km values of 2.91 and 1.08 mM were determined for tetrahydrofolate and serine, respectively. The effects of pH, of temperature and of some potential inhibitors were determined. The enzyme was also partially purified from a pyrimethamine-resistant strain of P. chabaudi and subjected to the same regime. No differences between the enzymes from the two sources could be detected. It would appear that the changes in properties in the enzymes dihydrofolate reductase and thymidylate synthetase associated with the development of drug resistance in P. chabaudi were not reflected in any obvious alterations in serine hydroxymethyltransferase.
丝氨酸羟甲基转移酶（EC 2.1.2.1）从查巴迪疟原虫的乙胺嘧啶敏感株中部分纯化得到。四氢叶酸和丝氨酸的米氏常数分别测定为2.91 mM和1.08 mM。测定了pH、温度和一些潜在抑制剂的影响。该酶也从查巴迪疟原虫的乙胺嘧啶抗性株中部分纯化，并进行相同的实验。未检测到两种来源的酶之间存在差异。看来，与查巴迪疟原虫耐药性发展相关的二氢叶酸还原酶和胸苷酸合成酶的性质变化，在丝氨酸羟甲基转移酶中未表现出任何明显改变。
